This invention relates to a method and arrangement for removing oil from a roll, in which, inside a rotatable shell, there is a fixed axle-beam, supporting loading shoes acting on the inner surface of the shell, and in which roll there are devices for removing oil from the roll, comprising an oil guide attached to the loading shoes, a collector trough, and oil-removal piping, of which the oil guide is arranged to form an oil jet directed into the roll, the removal of the oil from the roll being arranged to take place with the aid of the pressure difference.
Problems with deflection-compensated rolls include oil frothing and poor oil removal from inside the roll. In addition to oil leaking from the loading shoes, oil may be sprayed against the inside of the roll shell to cool or heat it. It is important that the oil is collected as soon as possible from inside the roll, so that frothing of the oil, and thus the air mixed with it, remains as little as possible. When the roll rotates, a film of oil travels around its inner surface, colliding with the stationary loading shoes. In the solution according to U.S. Pat. No. 5,853,359, the lubricating oil colliding with the loading shoes is allowed to flow by gravity to a lower trough, from which it is sucked out of the roll. If the loading shoes are low down, a special scraper is used, from which the oil flows into the trough in a corresponding manner. Such a construction demands a considerable amount of space, which is not available in most rolls. A somewhat similar construction is disclosed in Finnish patent application 982045, in which the gravity-induced flow is directed to a special collection space, which may be located as a low construction on the outer surface of the cylindrical axle. WO publication 98/38381 discloses a special guide, to be attached to the loading shoes, by means of which a jet, directed towards a trough beneath, is formed from the film of oil traveling along the inner surface of the roll. In this case, the oil-removal guide must be set at a higher level, because removal takes place, at least partially, by gravity into the lower trough. A corresponding solution cannot be used in connection with a loading shoe set at a lower level.
The present invention provides a method and an arrangement embodying it, which will permit the removal of oil in any position at all.
The method for removing oil from a roll, in which, inside a rotatable shell, there is a fixed axle beam, which supports loading shoes directed against the inner surface of the shell, and in which roll there are devices for removing the oil from the roll, comprising an oil guide attached to the loading shoes, a collector trough and oil-removal piping, of which the oil guide is arranged to create a jet of oil directed inside the roll and the transfer of the oil out of the roll is arranged to take place with the aid of a pressure difference, is characterized in that the collector trough is located a short distance from the oil jet and the related auxiliary guide, which, together with the oil guide is arranged to guide and channel the oil jet against the trough, and that the oil is removed to the outlet pipe through a low gap in the bottom of the collector trough.
The arrangement in a roll equipped with loading shoes, in which, inside a rotatable shell, there is a fixed axle beam, supporting the loading shoes directed against the inner surface of the shell, and in which shell there are devices for removing oil from the roll, comprising an oil guide attached to the loading shoes, a collector trough, and oil-removal piping, of which the oil guide is arranged to form an oil jet directed inside the roll and the transfer of the oil out of the roll is arranged to take place with the aid of a pressure difference, is characterized in that the collector trough includes an auxiliary guide and that it is located at a short distance from the oil guide of the loading shoe, in such a way that it turns the oil jet to the bottom of the collector trough, and that there is a gap in the bottom of the collector trough leading to the outlet pipe.
Utilizing the method according to the invention, oil is removed rapidly and with a good degree of control, in a small space. According to one preferred embodiment, each loading shoe incorporates a guide of the same width as the shoe, for creating an oil jet, whereas the collector trough receiving the oil and its auxiliary guide and removal pipe are essentially the same width as the roll shell.
These and other features and advantages of the invention will be more fully understood from the following detailed description of the invention taken together with the accompanying drawings.